Abstract:In this study，gold nanoparticles（AuNPs）with uniform particle size were prepared by the sodium citrate reduction method.The fluorescence probe was prepared by coupling AuNPs with ochratoxin A（OTA）antibody through electrostatic adsorption，and the resultant product was coupled with 6-carboxyfluorescein（6-FAM）-modified oligonucleotide chain（ssDNA）through gold sulfur bond.AuNPs were used to quench the fluorescence group signal in a close range and 1，4-dithiothreitol（DTT）was used to dissociate the oligonucleotide chain to establish a method for rapid detection of OTA in cereals based on oligonucleotide chain signal amplification.The limit of detection of the method was 0.004 4 μg/L with good specificity under the optimized conditions.The OTA content in corn，rice，and oat was determined by this method.The results showed that the added recovery rate was in the range of 91.2%-102.3%，and the coefficient of variation was less than 10%.The detection results were close to those of ultra-performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS），which proved that the method could be used to detect the content of OTA in cereals.